Replace WIDEVINE_CDM_AVAILABLE with a gyp define 'enable_widevine_cdm'.

media/media_options.gni

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 declare_args() {
   # Allows distributions to link pulseaudio directly (DT_NEEDED) instead of
   # using dlopen. This helps with automated detection of ABI mismatches and
   # prevents silent errors.
   link_pulseaudio = false
 
@@ skipping 31 matching lines @@
   }
 
   # Enables the MPEG2-TS stream parser for use with Media Source. Disabled by
   # default since it's not available on the normal Web Platform and costs money.
   enable_mpeg2ts_stream_parser = false
 
   # Enables browser side Content Decryption Modules. Required for android where
   # the typical PPAPI based CDM is not available.
   enable_browser_cdms = is_android
 
+  # Widevine CDM is enabled by default for Chrome builds, and is a platform
+  # feature on Android.
+  enable_widevine = is_chrome_branded || is_android
+
+  # Widevine is distributed as a component for Mac and Win.
+  widevine_cdm_is_component = is_mac || is_win

[ddorwin, 2014/12/02 23:31:56]

ditto

+
   # TODO(GYP): This should be a platform define.
   is_openbsd = false
 }